The real question about the double converters for the UFX mic channels is "was it worth it"? The configuration should deliver a 3dB improvement in quantisation noise floor - from the spec (and my informal testing) it appears to deliver 2dB (an example of a "real world" result). The improvement is in my view immaterial when using a mic gain of about 30dB or more (still no official spec of Ein in the manual).
What is rather more interesting is whether there has been any attempt at cancelling non-linearity. If the pair of converters are connected in opposite phase and the resulting output subtracted, the effect is that a positive going input voltage is ramping up in one converter and ramping down in the other. If there is any systematic non-linearity in the process (especially even-order transfer or time response), then the generated components may cancel, resulting in a more linear (voltage-in/digital-value-out and voltage/time) transfer characteristic. This improvement would probably be evident at any mic gain setting. But it is not a proposition I can really test.
(A response along the "House of Cards" lines - "You may think that. I couldn't possibly comment." - is not unexpected.)
De gustibus - et sonus - non est disputandum